Method and apparatus for drying



Oct. 18, 1938.- R. H. BUCKWALTER 7 METHOD AND APPARATUS FOR DRYING Filed Nov. 17, 1934 Patented Oct. 18 1938 METHOD AND APPARATUS FOR DRYING Ross H. Buckwalter, Joliet, Ill.,- assignor to Star Peerless Wall Paper Mills, Chicago, 111., a corporation of Illinois Application November 17, 1934, Serial No. 753,457

7 Claims.

My invention relates to a method and apparatus for drying and is concerned primarily with the removal of moisture from a continuously moving web of material.

The principal object of my invention is to devise a method of drying and an apparatus for eifectuating the same in which a continuously moving web, arranged in a succession of overlapping folds, is subjected to the action of a drying 10 medium, usually heated air, the web being turned over at periodic intervals to expose both sides thereof to the medium.

A further object is to devise an apparatus of the type indicated in which the drying medium is so 15 directed relative to the moving web that the latter is characterized by a floating or billowing action that enhances and expedites the drying operation.

These and further objects of my invention will be set forth in the following specification,

20 reference being had to the accompanying drawing and the, novel means by which said objects are efiectuated will be definitely pointed out in the claims.

In the drawing:

Figure 1 is a diagrammatic, sectional elevation of my improved apparatus, as taken on the line l-I in Fig. 2, looking in the direction of the arrows.

Fig. 2 is a section taken along the line 22 in Fig. 1, looking in the direction of the arrows.

Fig. 3 is a sectional, perspective view of a modified duct construction for feeding the drying medium to the moving web.

The apparatus disclosed in this application is .35 more particularly intended for use in connection with a process of making washable wall paper as disclosed in my co-pending application, Serial No. 753,456 filed on even date herewith, because of its capacity for handling a large 40 quantity of paper within a comparatively restricted space, thus avoiding the otherwise necessity of lengthening the production line by the addition of the festoon type of drying rack which is ordinarily employed to dry wall paper. In

" many installations, such a change would necessitate the demolishing and rebuilding of a portion of the factory, but this step is avoided by the use of my apparatus. For purpose of illustration, the apparatus will be described in connection with the drying of a web of paper, but it will be understood that the invention is not so limited, and is susceptible of other and broader uses in the field of drying.

Referring to Figs. 1 and 2 of the drawing, the

55 numeral [0 represents standards which may be and more important parts, of the apparatus as hereinafter described.

At the right end of the apparatuses viewed in Fig. 1, a shaft I6 is journaled in and extends between the side rails II and has affixed to one extremity thereof a gear I! which may be appropriately driven by any suitable source of power (not shown). A roll I8 is mounted on the shaft I6 between the side rails H and a similar roll 19 is also appropriately journaled in the same rails at the opposite end of the machine. Over this pair of rolls ,operates an endless belt 20 whose upper or web-supporting portion is moved continuously at some predetermined and constant speed toward the right, as viewed in Fig. 1.

A sprocket 2| is also mounted on the shaft IE- -and through a chain 22 drives a sprocket 23 fixed to the extremity of a shaft 24 which is journaled in and extends between the side rails l3. A roll 25 is mounted on the shaft 24 between these rails and a similar roll 26 is mounted for rotation between the same side rails at the opposite end 01' the apparatus. Over the rolls 25 and 26 moves an endless belt 21 at the same speed as the endless belt 20 and the upper or web-supporting portion of the former belt moves in the same direction as the corresponding portion of the latter belt.

A sprocket 2B is also mounted on the shaft 24 and through a chain 29 drives a sprocket 30 provided on a shaft 3| that extends between and is journaled in the side rails I5. A roll 32 is fixed to the shaft 3i between the rails l5 and over this roll and a pair of spaced, guide rolls 34, which are located at the opposite end of the apparatus, operates an endless belt 33. The opposite extremity of this belt operates over a roll which is located somewhat to the left of the apparatus, as viewed in Fig. l, and at an elevation below that of the roll 32, so that between the roll 35 and the upper guide roll 34, the web-supporting por-- tion of the belt 33 is inclined to the horizontal, while between the upper guide roll 34 and the roll 32, the web-supporting portion of the belt 33 is substantially horizontal and parallel to, and moving in the same direction and at the same rate of speed, as the corresponding portions of the belts 20 and 21.

A gear 36 meshes with the gear l1 and is mounted on a shaft 31 that is bridged between and is journaled in the side rails l2 and, between these rails, a roll 38 is fixed to the shaft 31. A similar roll 40 is rotatably mounted between the rails I2 at the opposite end of the apparatus and over the rolls 38 and 40 operates an endless belt 39 whose upper or web-supporting portion moves at the same rate of speed as the corresponding portion of the belt 20, but in the opposite direction.

A sprocket 4| is fixed to the extremity of the shaft 31 and through a chain 42 drives a sprocket 43 that is mounted on the extremity of a shaft 44 which is journaled in and is bridged between the side rails l4. A roll 45 is fixed to the shaft 44 between the rails l4 and an endless belt 46 operates over the roll and a similar roll 41 that is 1'0- tatably mounted on and between the rails l4 at the opposite end of the apparatus. The upper or web-supporting portion of the belt 46 operates in the same direction as, and at the same rate of speed, as the corresponding portion of the belt 39.

From the foregoing, it will be understood that the drying apparatus comprises a plurality of endless belts which are spaced from each other in a vertical direction and whose directions of movement are so controlled that a web of material that is deposited, for'example, on the belt 33, will follow a substantially sinuous path in moving through the apparatus. This arrangement makes for compactness and a capacity for handling a relatively large quantity of material within a rather restricted space.

In order to supply a drying medium to the apparatus, which medium is usually heated air, cooperative pairs of ducts 48 extend lengthwise of the apparatus on opposite sides of, and at substantially the same elevation as, the web supporting portions of the several belts. Each of these ducts is provided with a plurality of apertures 49 and the ducts are connected by means of a manifold 50 to a suitable source of heated air. The emission of the air from the several apertures 49 may be controlled by suitable dampers that are located in convenient locations along each duct. In Fig. 1, there has been illustrated two manifolds 50 for feeding air to the several ducts, but the arrangement and number of such manifolds may be varied as desired.

As an important feature of my apparatus, I

, prefer to employ a so-called crimping mechanism comprising a pair of cooperating rolls 52 and 53 which draw therebetween a continuous web of material 54 and deposit the same upon an endless belt 55 that is supported at one end upon the usual roll 56. The rolls 52 and 53 are driven at some constant speed and such that the peripheral speed of these rolls is somewhat greater than the linear speed of the endless belt 55. The web 54 will therefore be delivered to the .belt 55 in a somewhat crimped arrangement, that is, in a succession of overlapping and irregularly formed folds, as illustrated diagrammatically in Fig. l.

The roll 56 is so located that the folded web 54 will be deposited on the inclined portion of the belt 33. The web will therefore enter the drying apparatus in a succession of overlapping folds and at the travel end of'each belt within the drying apparatus per se, the successive web folds are tumbled indiscriminately onto the web supporting portion of the next lower belt. This action not only completely reverses the position of the web, but also reverses the direction in which the several folds lie.

By this method of handling the web, it is possible to considerably hasten and render the drying operation more effective because it is contemplated that the heated air will issue from the ducts at such a velocity and in such a volume that the successive folds will be subjected to a substantially floating or billowing action due to the folds being lifted or separated by the impact of the air streams directed against the opposite side edges and between the folds of the web. The dampers may be adjusted tosecure a substantially uniform delivery of the air throughout the length of the ducts and also to secure any desired degree of drying by varying the quantity of air impinging on the web. Moreover, the periodic turning over of the moving web and the reversing of the positions of the folds insures a complete drying of both sides of the web, while by crimping and moving the web in a sinuous path through the apparatus, the capacity-space efficiency of the latter is obviously increased over that of the festoon type of drying rack. After contacting the folds of the web, the air passes freely away from tlv. apparatus and may be exhausted to the atmosphere by suitable fan equipment.

In Fig. 3 is illustrated a modified typeof duct 58 which is generally similar to those already described, except that a longitudinal slit 59 is substituted for the spaced apertures 49. Dampers may also be and are preferably employed with this type of duct.

I claim:

I. A method of drying a continuous web of material comprising forming the same in a succession of overlapping folds, and carrying the folded web past streams of a drying medium directed against the opposite side edges of the web, the impact of the streams on each other and on the web causing the latter to have a billowing action sufficient to separate the folds for intimate contact with the medium.

2. A method of drying a continuous web of material comprising forming the same in a succession of overlapping folds, and carrying the folded web along a succession of substantially horizontal courses in a substantially sinuous path from an upper to a lower elevation while exposing the web to streams of a drying medium directed against the opposite side edges of the web, the impact of the streams on each other and on the web causing the latter to have a billowing action sufficient to separate the folds for intimate contact with the medium. alternate courses of the web moving in the same direction and the transferof the web between successive courses beingeifected by a gravity drop of the web folds.

3. A drying apparatus for drying a web of material comprising a plurality of moving, endless belts spaced from each other in a vertical direction, the web supporting portions of alternate belts running in the same direction whereby the web is moved in a sinuous path through the apparatus, means for continuously delivering a web to the uppermost belt in a succession of overlapping folds, and means extending along the opposite sides of the supporting portions and positioned to direct streams of a drying medium against the opposite side edges of the folded web.

4. A drying apparatus for drying a web of masion of folds, and carrying the. folded web past terial comprising a continuously moving, endless belt, means for continuously delivering a web to the belt in a succession of overlapping folds, and means extending along the opposite sides of the web supporting portion of the belt and positioned to directstreams of a drying medium against the opposite side edges of the folded web in suflicient volume and at a sufiicient velocity to cause the Web to have a billowing action suflicient to separate the folds for intimate contact with the medium.

5. A method of drying a continuous web of material comprising forming the same in a succession of reclining folds, and carrying the folded web past streams of a drying mediumdirected against the opposite side edges of the web, the impact of the streams on each-other and on the web causing the latter to have a billowing action sufficient to separate the sides of the folds from each other, respectively, and from the remainder of the web for intimate contact with the medium.

6. A method of drying a continuous web of material comprising forming the same in a successtreams ofa drying medium directed against the opposite side edges of the web, the impact of the streams on each other while passing through the ,folds above and below the web imparting a shaking movement to the web and facilitating the drying action of the medium.

'7. A drying apparatus for drying a web of material comprising a continuously moving, endless belt, means for continuously delivering a web to the belt with spaced portions of the web resting on the belt and other portions spaced from the belt and forming therewith ducts extending transversely of the web and means extending along the opposite sides of the web supporting portion of the belt and positioned to direct streams of a drying medium against the opposite side edges of the web, the impact of the streams on each other while passing through the ducts above and below the web imparting a shaking movement to the web and facilitating the drying action 01' the medium.

ROSS H.BUCKWALTER. 

